Multi-Stack Microservices Demo (Upsun Edition)

Overview

This project is a comprehensive showcase of a polyglot microservices architecture running on Upsun. It demonstrates how to manage multiple technologies (Node.js, Go, Python, Java), shared services, and complex routing within a single Git repository using Git-Driven Infrastructure.

Special Remarks for Demoing

This example is for learning purposes only and is not intended as a starting point for an actual production instance.

In this version, the project has been migrated to the Upsun Unified Configuration format, consolidating all infrastructure definitions into a single .upsun/config.yaml file.

Architecture Highlights

Applications

All application containers are defined under the applications: key in .upsun/config.yaml:

• Frontend: A React application accessible at the apex domain.
• API Gateway: A Node.js (KrakenD) gateway that proxies traffic to internal microservices.
• Microservices: Four distinct services written in Go, Java, Python, and Node.js.
• Identity & Security: A managed Keycloak instance and a HashiCorp Vault instance.
• Workers: Two background workers (Python and Go) demonstrating asynchronous processing and the Flex resource model (defined with low CPU/RAM footprints).
• Shared Storage: A Network Storage service mounted to the Python and Go applications/workers for shared data persistence.

Services

Defined under the services: key:

• PostgreSQL: A shared database for microservices, configured with multiple schemas and specific endpoints (admin, reporter, and importer) to demonstrate granular access control via relationships.
• MariaDB: A dedicated database for the Keycloak instance.
• Network Storage: A persistent shared filesystem for polyglot data exchange.

Routing

Public exposure is managed under the routes: key:

• https://{default}/ -> Frontend
• https://api.{default}/ -> API Gateway
• https://keycloak.{default}/ -> Keycloak
• https://vault.{default}/ -> Vault

Core Upsun Concepts Demonstrated

1. Unified Configuration

All infrastructure—including the 10+ application containers and their supporting services—is defined in a single file: .upsun/config.yaml. This replaces the legacy .platform/applications.yaml, .platform/services.yaml, and .platform/routes.yaml structure.

2. Flex Resource Model

Each container in this demo has explicitly defined resources (CPU and RAM). This allows you to right-size the Java service (which may need more memory) differently than a lightweight Go worker, optimizing both performance and cost.

3. Inter-Service Communication

Internal routing is "opt-in." Applications can only communicate with services or other applications if a relationship is explicitly defined. This demo shows the API Gateway linked to the internal microservices, keeping them shielded from the public internet.

4. Ephemeral Environments

Because this is on Upsun, every Git branch creates a byte-for-byte clone of this entire stack. Running upsun environment:branch my-feature will clone all 10 apps and 2 databases into a preview environment with its own unique URLs.

Deployment & Management

To interact with this project, use the Upsun CLI:

• Deploy changes: upsun push
• Access a container: upsun ssh -a [app-name]
• Scale resources: upsun resources:set
• Stream logs: upsun log

Contribution

• Initial demo by Ori.
• Ported to Upsun Unified Config by @Gemini-Upsun-Expert.